鉴定结论是鉴定人依照合法程序和科学方法对案件专门性问题进行分析、鉴别和判断所提供的结论性意见。由于鉴定人的专业水平和知识结构的不同、研究能力大小的差异、鉴定采用的方法和设备先进程度的差别、鉴定对象复杂层次的难易,鉴定标准依据等级的区别,以及其他因素介入的深浅,常引发鉴定结论的争议,一次鉴定难以确认争议的事实,导致在一个案件中同一个专门性问题经两次或多次鉴定出现性 The appraisal conclusion is that the appraiser analyzes, identifies and judges the case-specific issues according to legal procedures and scientific methods. Due to the difference of expert's professional level and knowledge structure, the difference of research ability, the difference of advanced method and equipment used in identification, the difficulty of complex level of identification object, the difference of identification standard according to grade and the depth of other factors involved, Often lead to controversial conclusions of the appraisal, the fact that the identification is difficult to confirm the dispute, resulting in two or more occasions identification of the same special problems in a case